Hoisting device



Dec. 15, 1959 c. H. ARNOLD HOISTING DEVICE Filed Nov. 15, 1956 2 Sheets-Sheet 1 IN V EN TOR.

BY 042152 A. ABA/0L0 Dec. 15, 1959 c. H. ARNOLD 2,917,279

HOISTING DEVICE Filed Nov. 13, 1956 2 Sheets-Sheet 2 I 2: U M

/ I INVENTOR.

E g 3 Q oaerae H Azuoz D i i; 5 B Y a a L 2 7 y wane United States Patent HOISTIN G DEVICE Carter H. Arnold, Redwood City, Calif.

Application November 13, 1956, Serial No. 621,662

4 Claims. (Cl. 254-150) v This invention relates to hoisting devices of the type that may be employed to support scaffolds or to pull rope and is similar in some respects to the hoist shown in my United States Letters Patent No. 2,742,261, dated April 17, 1956.

In. the above noted patent there is disclosed a hoisting device adapted to be employed with a hoist having a loaded run' and an unloaded run and in which a plurality of loops are formed, portions of which are wrapped around the drum and portions wrapped around means spaced from the drum. By the invention of the cited patent the hoist and its supported structure may be moved along the length of a rope, or the hoist, if held stationary, may be employed to pull rope relative thereto.

The instant invention, although having the same general mode of operation of the above noted invention, has certain advantages thereover.

In the cited patent the rope is subjected to sudden changes in direction which tend to increase the bending stresses therein. In addition, the means for transferring the rope from one winding to the adjacent winding must be relatively strong to withstand the relatively high tensions in the rope, thus increasing the cost of manufacture and, in some instances, resulting in relatively high friction losses.

The main object of the present invention is therefore to overcome certain disadvantages of the above noted type of hoist.

Another object of the invention is the provision of a single drum hoist that does not subject the'rope to sharp changes in direction and which therefor does not build up high stresses in the rope.

Still another object of the invention is the provision of a. hoist which is relatively inexpensive to construct and which minimizes power losses due to friction.

Other objects and advantages will be seenin the following specification and drawings:

Fig. l is a top plan view of the preferred form of the invention with the upper portions of the hoist removed for clarity; I

Fig. 2 is a side elevation of the hoist of Fig. 1 with portions broken away; i

Fig. 3 is a side elevation of the hoist of Fig. 1;

Fig. 4 is a side elevation of a modified form of hoist with portions broken away to show internal structures;

Fig. 5 is a fragmentary top plan view of the hoist of Fig. 4 showing only the drum and guides;

Fig. 6 is a fragmentary cross section through the drum and block of Fig. 1 showing a modified form of guide;

Fig. 7 is atop plan view of a hoist showing another modified form of guide means;

Fig. 8 is an enlarged fragmentary sectional view through the drum and rope of Fig. 7 showing the cooperation between the guide means and the rope; V

Fig. 9 is a schematic plan view of an expanded drum showing another modified form of the invention. 7

In detail, and with reference to Figs. 13 the invention comprises a housing consisting of a of spaced op- 2 posed parallel side plates 1, 2 spaced apart by means of spacers 3 and secured by bolts 4 and nuts 5.

Extending between and rotatably supported in side plates 1, 2 is a shaft 8 to which is fixedly secured a drum 9.. In the preferred form of the invention the drum 9 is provided with five circumferentially extending grooves 1014 (Fig. 1) that are complementary in cross section to the cross section of the rope 15 that is adapted to be received therein. The lands 16 between the grooves are rounded as best seen in Figs. 1, 6 so that no sharp edges are presented to the rope.

Grooves 10-14 are adapted to receive therein windings of rope 15 which windings are indicated by numerals 2024 to correspond with grooves 1014 respectively. In Fig. 1 the loaded run 26 of rope 15 enters groove 10 and winding 20, which is a continuation of said loaded run, extends around substantially the entire circumference thereof before it is deflected into the adjacent groove 11 in a manner now to be described.

Extending between side plates 1, 2 and secured thereto as by bolts 27, 28 respectively is a relatively heavy elongated block 29 which is positioned closely adjacent the periphery of drum 9 with its adjacent surface 30 formed to a circular arc.

Block 29 is bored to receive pins 4044 which extend radially inwardly of the drum and into grooves 10--14 respectively. As will be understood the exact position of the pins id-44 with respect to their associated grooves is not critical. Pins 40 -44 may be press fitted in block 29 or may be screw threadedly secured therein in any convenient manner.

It will be apparent that as drum, 19 rotates counterclockwise (Fig. 2) loaded run 26 is wound o'nto groove 10 in the form of winding 20 and the latter is deflected or shunted by pin 40 into theadjacent groove 11 (Fig. 1) to form winding 21. Similarly, pin 41 guides winding 21 from groove 11 into groove 22 and so on.

Winding 24, inextension of the unloaded run 34 (Fig. 2) of the rope 15 is acted upon by a tensioning device generally designated 32 which is fully disclosed in my Patent No. 2,756,947, issued July 31, 1956 and which is not described herein in. detail.

The drum 9 is drivenby a gear 37 mounted on shaft 8 which cooperates with a pinion 38 carried by shaft 39 extending between side plate 1, 2. Crank assembly, generally designated 46 (Fig. 3) is employed to drive pinion shaft 39 as described in said Patent No. 2,756,947.

The above noted drive mechanism is described in detail in Patent No. 2,756,947 but the particular means for driving drum 9 is not critical insofar as the present invention is concerned. For example, power means may be employed if desired.

Referring again to Fig. 2 it is seen as drum 9 is driven in a clockwise direction, that is, as loaded run 26 is unwound from groove 10, pin- 41 serves to deflect winding 21 into groove 10 and pin 42 deflects winding 22 into groove 11 and'so on. It is because of the above-described action of the windings that the pinsv 40--44 are positioned in a row that is slantingly disposed relative to the side plates 1, 2. If said pins were in a row at right angles to said side plates the grooves would have to be spaced apart so much that the resultant structure would be too bulky, Furthermore, the arrangement shown avoids jamming of the rope between adjacent pins especially as the direction of the drum reverses.

It is preferable that pin 40, that is, the guide that first engages-the loaded end of the rope, be positioned closely adjacent said loaded run. In this manner the first winding 20 encompasses almost the entire circumference" of groove10 before it is deflected into groove 11. In other words, the tension in the loaded end of the rope is reduced as much as possible by the friction between the rope and 3 groove 10 before the winding is deflected into the adjacent groove. This also considerably reduces the lateral force exerted on pin 40 by the juncture 49 between windings 20, 21.

It should also be noted that the rope juncture 49 between windings 20, 21 and the other connecting junctures Although five grooves are shown on drum 9 it will be apparent that more or less grooves may be employed as desired depending on the loads and speeds involved and the type of wire used. However by the above described arrangement it will be apparent that the grooves may be placed very close together which increases the number of grooves possible on a given size drum.

Although the force of the rope against the guide pins is not great, friction may be reduced somewhat by providing a roller 51 (Fig. 6) on a pin 52 which may be secured to the block 29 as described above.

Another modification of the invention is seen in Figs. 7, 8 wherein a shaft 52 is substituted for block 29 and is provided with a plurality of circular flanges 53 in lieu of pins. Shaft 52 may be rotatably secured in bearings 54, 55 respectively carried by side plates 1, 2. In this case it will be understood that the circular flanges are of different diameters so as to extend into their associated grooves.

The present invention also contemplates the use of a smooth drum. In this connection it should be noted that the windings on the drum should preferably be in parallel planes substantially at right angles to the axis of the drum and it is necessary to prevent the windings from walking axially of the drum upon rotation of the latter. In the above described preferred form of the drum the grooves constitute the means for holding the windings in such parallel planes. However the windings may also be maintained in their proper position on a smooth drum.

Figs. 4, illustrate one construction employing a smooth drum. In this case the smooth cylindrical drum 59 receives the windings as described above and circumferentially spaced guides 60-63 are provided extending between and secured to side plates 1, 2. Each guide is provided with a plurality of slots 64 which receive the windings therein and hold them against axial movement in much the same manner as the grooves on drum 9 hold the windings againstaxial movement.

Fig. 9 illustrates schematically how the same type of guides as those shown in Figs. 4, 5 may be employed without requiring use of the guide pins or the block 29. In this case guides 7073 extend between the side plates of the hoist, but are arranged with their grooves 74 in uniformly staggered relationship so that the corresponding portions of each winding are shifted the same amount axially of the drum 69. In other words, each guide 70-73 acts as a means for holding the windings in fixed paths and at the same. time guides the rope from one winding to another. Although the windings of Fig. 9 are not in parallel planes, corresponding portions of said windings are parallel to each other and this satisfies the requirements of the method of the present invention.

It will be understood that the smooth drum embodiments of the invention result in relatively high localized pressure between the rope and the .drum whereas such pressure is distributed to a greater extent when a grooved drum is used. For this reason a grooved drum is preferable in most high power applications of the invention whereas a smooth drum is preferable from an initial cost standpoint if excessive pressures are not thereby created.

An obvious extensionof the structure of Fig. 9 is to provide a continuous block completely encircling the smooth drum and provided with radially inwardly opening helical grooves for receiving the windings therein.

However it will be understood that such helical grooves, though continuous, still provide holding and guiding means at a plurality of points around the drum for holding the windings in fixed paths just as the grooves in a grooved drum provide similar means.

The very specific description of the forms described is not to be taken as restrictive of the invention as it is obvious that minor variations in design may be made without departing from the invention as described in the following claims.

I claim:

1. A hoisting device for handling a rope having a loaded run and an unloaded run comprising: a housing, a drum rotatably supported on said housing, a first circumferentially extending groove formed on said drum and adapted to receive said loaded run therein a second circumferentially extending groove formed in said drum parallel to said first groove, said rope being formed intermediate said runs to provide first and second windings in said first and second grooves respectively with the connecting juncture between said windings in engagement with said drum, a guide carried by said housing and in engagement with said rope at said juncture for guiding said rope from said first groove into said second groove, said guide being positioned adjacent the point at which said loaded run is received in said first groove whereby said first winding engages said first groove for substan tially the circumference of said drum.

2. A hoisting device for handling a rope having a loaded run and an unloaded run comprising: a housing, a drum rotatably supported on said housing, a first circumferentially extending groove formed on said drum and adapted to receive said loaded run therein a second circumferentially extending groove formed in said drum parallel to said first groove, said rope being formed intermediate said runs to provide first and second windings in said first and second grooves respectively with the connecting juncture between said windings in engagement with said drum, a first guide carried by said housing and in engagement with said rope at said juncture for guiding said rope from said first groove into said second groove when said drum is rotated in one direction and a second guide carried by said housing for guiding said rope from said second groove into said first groove when said drum is rotating in the opposite direction.

3. In combination with a length of rope, a hoisting device comprising: a housing, a rotatable drum mounted on said housing, a plurality of windings formed intermediate the ends of said length and wound around said drum in side by side relation, the opposite end portions of said length being free from said drum and one end portion being adapted to be Wound onto said drum upon rotation of the latter as the opposite end portion is wound off, whereby the number and extent of said windings remain the same, means for holding said windings against axial movement during rotation of said drum and means carried by said housing for deflecting said rope from one of said windings to an adjacent winding during said rotation and while saidrope is in engagement with said drum.

4. In combination with a length of rope, a hoisting device comprising; a housing, a rotatable drum mounted on said housing, a plurality of windings formed intermediate the ends of said length and wound around said drum in side by side relation, the opposite end portions of said length being free from said drum and one end portion being adapted to be wound onto said drum upon rotation of the latter as the opposite end portion is wound off, whereby the number and extent of said windings remain the same, means for holding said windings against axial movement during rotation of said drum and means carried by said housing for deflecting said rope from one of said windings to an adjacent winding during said rotation and while saidrope is in engagement with said drum, said holding means comprising a first guide fixedly 5 secured to said housing, and saiddeflecting means comprising a second guide fixedly secured to said housing and in engagement with said rope adjacent the juncture between an adjacent pair of windings.

References Cited in the file of this patent UNITED STATES PATENTS 2,258,889 Graham Oct. 14, 1941 6 Mackmann Mar. 19, 1946 Mahnke Feb. 21, 1950 Allenbaugh Dec. 15, 1953 FOREIGN PATENTS France Sept. 8, 1954 

